62 THE NOSE AND PARANASAL SINUSES
development. The external tumour is subcutaneous, firm and elastic to the
touch, and it must be distinguished from a dermoid cyst. The intranasal type
resembles a small nasal polypus on inspection and it may appear in the nasal
vestibule. It is firm to the touch with a probe and does not enlarge when the
baby cries, a fact which distinguishes it from an encephalocele. The glioma is
composed of neuroglial tissue and astrocytes, and is not malignant. It should
be removed completely.
Encephalocele. This is a herniation of dura mater which enters the nose
through the foramen caecum or through a dehiscence in the cribriform plate
of the ethmoid bone. The cyst contains cerebrospinal fluid and occasionally
cerebral tissue. It is smooth, freely movable on its stalk, readily compressible
and enlarges with crying. In view of its composition it is dangerous to
puncture the cyst to determine the nature of its contents in case an intracranial
infection results. The removal is a neurosurgical one and the deficiency in the
floor of the skull is closed at the same time.
Fig. 27. Dennoid of the nose in a child aged
18 months. The sinus opening on the external
nose has become infected.
Dennoid Cyst. This is an external midline cyst on the dorsum of the nose
which contains hair and amorphous material. It may open on to the surface by
a small sinus (Fig. 27) through which hair may protrude. This serves to
distinguish it from an external glioma. The cyst tends to extend widely
beneath or between the nasal bones towards the base of the skull, so that
surgical removal may be an extensive procedure which may necessitate
Rhinophyma. This condition occurs almost entirely in males past middle age
in whom it may produce considerable deformity thus causing much distress
on account of the disfigurement (Plate HI, 1). It is a hypertrophy of the
sebaceous glands of the tip of the nose and produces a marked swelling of the
nasal apex which becomes bulbous in appearance. The skin is coarse and
pitted and has an oily appearance because of the excessive secretion of
sebaceous material. It is red or blue in colour from vascular engorgement.
Treatment consists in shaving off the excess tissue to trim the nose to a
suitable size after which a skin graft may be applied.